RFC Perl for education
For some time now, I have an idea of ePerl in my head. A subset of Perl or Perl in a sandbox. You might guess why? well Perl is great language, backwards compatibility makes your old code still run, even if some of the ancient designs are considered wrong nowadays. It’s all fine, except it’s not suitable for education.
In my opinion, to make Perl more acceptable in School/University curriculum we need to sell it to lazy teachers/lecturers, who need something like:
- Current best practises upfront
- No backwards compatibility
- Strict, warnings, utf8 and newest Perl features on by default
- Sub signatures and postfix dereferencing should be on and without experimental warnings
- Most of the greatest CPAN modules should come preinstalled, and I am really talking about modules that helps beginners! i.e. Devel::REPL, Devel::DidYouMean, Moo, and many many other like Mojolicious, Dancer, Catalyst, whatever…
- Forbid/remove special cases like split emulating awk.. or indirect object notation and many other silly leftovers
- etc. etc.
Other languages break backward compatibility, they make current developers angry, but future generation don’t need to care what or why happened 10 years ago. Don’t get me wrong, backwards compatibility is superb, but it’s biggest Perl’s weakness today. Beginners don’t care about the core nor how to achieve thing X in Y different ways. Furthermore, this would allow them to learn quicker and safer Modern Perl.
What do you think?
=== P.S.
...While I am writing about Perl5, I believe Perl6 will have exact same problem...
...and yes.. I am aware of breaking CPAN. Though if it was running in a sandbox, it would still be able to escape and use CPAN modules..
… I believe Perl is unique language, that needs it, because:
- Modern Perl’s best practises are rapidly changing, but core is very very behind ( due to backwards compatibility & that feature must first appear on CPAN )
- Perl’s “There is more than one way to do it”....
I am proud Perl developer since 2014.
twitter: https://twitter.com/vytasdauksa
One of the problems with Perl5 you haven't addressed is the downgrading of strings. If you deal with strings with characters above 127 they can be arbitrarily downgraded from utf8 (or other specified codepage) to Legacy Perl Strings.
Perl really needs a Major Release that breaks backwards compatibility. Then all string oriented operations can default to utf8. And all of the cool new features can be turned on by default. Old features can be moved to compatibility modules or pragma to enable a smoother transition.
The rest of what you're talking about would be some sort of distribution on top of next generation Perl5. You might want to look at DWIM Perl (dwimperl.com) which is already bundling a huge set of popular modules.
amen!
> No backwards compatibility
Why?
> Strict, warnings, utf8 and newest Perl features on by default
Modern::Perl or a similar pragma.
> Sub signatures and postfix dereferencing should be on and without experimental warnings
Easily achievable with a pragma.
> Most of the greatest CPAN modules should come preinstalled, and I am really talking about modules that helps beginners! i.e. Devel::REPL, Devel::DidYouMean, Moo, and many many other like Mojolicious, Dancer, Catalyst, whatever…
Task::Kensho, dwimperl, or a custom Task::.
> Forbid/remove special cases like split emulating awk.. or indirect object notation and many other silly leftovers
indirect.pm for indirect object notation.
In any case, they do no harm — nobody forces the teachers to teach these features.
This ePerl should just be a pragma and a Task::, probably in a single distro. Which would be easy to write. No need to break backwards compatibility or to use a sandbox.
> No backwards compatibility
>> Why?
Due to different requirements. Perl for production needs to support what was done 10 years ago. Perl for education should enforce current best practices, hence can be more aggressive.
> Strict, warnings, utf8 and newest Perl features on by default
>> Modern::Perl or a similar pragma.
I agree.
> Sub signatures and postfix dereferencing should be on and without experimental warnings
>> Easily achievable with a pragma.
True, as some of the other things, but not all.
> Most of the greatest CPAN modules should come preinstalled, and I am really talking about modules that helps beginners! i.e. Devel::REPL, Devel::DidYouMean, Moo, and many many other like Mojolicious, Dancer, Catalyst, whatever…
>> Task::Kensho, dwimperl, or a custom Task::.
While both Task::Kensho and dwimperl are awesome, they do not achieve what I would like to see in Perl for education. Furthermore, they are NOT backed-up by Perl foundation..
> Forbid/remove special cases like split emulating awk.. or indirect object notation and many other silly leftovers
>> indirect.pm for indirect object notation.
Sure, again, via pragma you can disable indirect object notation and many others, but you can't forbid things like one/two argument open and etc. etc.
>> In any case, they do no harm — nobody forces the teachers to teach these features.
In my opinion it does harm. Pupils may solve an exercise in a way that an experienced Perl developer ( with 10 years of experience ) would struggle to understand without a compiler, and now we are talking about teachers who had no more then a month or two years of playing. Furthermore, I feel they are wasting their time by explaining "what modern perl is" with all the boilerplate..
>> This ePerl should just be a pragma and a Task::, probably in a single distro. Which would be easy to write. No need to break backwards compatibility or to use a sandbox.
Yes and No. Perl lost it's fight in education sector. It's a fact. Thanks to Gabor Szabo and many others, there are things like dwimperl, but as we see - it's not enough. First of all, such initiative to get back into education market should be backed up by Perl foundation, who therefore might find sponsor and do a proper research of why Perl is not there and what we can do to be there. I can only guess, that it is:
- backwards compatibility
- no proper interactive shell
- too much boilerplate
- undermarketing PDL and friends
- need of PBP v2
- sponsors
- visibility(?)
btw, pdl.perl.org is down at the moment.
What you're describing sounds a lot like Perl6, which seems to be quite useable already.
The major thing that's missing in Perl6 is ready-to-use frameworks like Dancer etc (but I assume some proto-versions of such frameworks are hiding on github somewhere..)
> Due to different requirements. Perl for production needs to support what was done 10 years ago. Perl for education should enforce current best practices, hence can be more aggressive.
Still, breaking backwards compatibility shouldn't be a goal.
> While both Task::Kensho and dwimperl are awesome, they do not achieve what I would like to see in Perl for education. Furthermore, they are NOT backed-up by Perl foundation..
It is easy to create a custom Task:: with exactly the modules you would like to see in Perl for education. Why do they need to be backed up by Perl foundation?
> Sure, again, via pragma you can disable indirect object notation and many others, but you can't forbid things like one/two argument open and etc. etc.
For one/two argument open, can't a pragma override open via CORE::GLOBAL? Most things are achievable via pragmas.
> In my opinion it does harm. Pupils may solve an exercise in a way that an experienced Perl developer ( with 10 years of experience ) would struggle to understand without a compiler, and now we are talking about teachers who had no more then a month or two years of playing.
Students will most probably only use what the teacher showed them to solve the exercises. At worst, ePerl could include a perlcritic policy — the teacher can reject solutions that fail it, or the eperl pragma could pull in criticism.pm, refusing to run code that does not follow the policy. Of course, all this is very much against the spirit of Perl, but if the teachers want this feature let them have it.
> Furthermore, I feel they are wasting their time by explaining "what modern perl is" with all the boilerplate..
If ePerl is a pragma, the only boilerplate is 'use ePerl;'. Even this can be avoided -- just ship an executable named eperl which runs perl -MePerl "$@".
> First of all, such initiative to get back into education market should be backed up by Perl foundation, who therefore might find sponsor and do a proper research of why Perl is not there and what we can do to be there.
Right, researching what the teacher want is the first step — we're just guessing here, and probably guessing incorrectly.
> - backwards compatibility
Not bad in itself.
> - no proper interactive shell
I've never found these useful, but ePerl can ship a REPL as a dependency.
> - too much boilerplate
Easy to fix (see above).
> - undermarketing PDL and friends
True.
> - need of PBP v2
> - sponsors
> - visibility(?)
No idea about these.
A simple Perl distribution with the features discussed above (a do-it-all pragma, useful modules as dependencies, maybe an eperl executable) would be easy to build and would solve most of the problems you've identified.
Perl didn't lose the fight in the education sector because of the language, but for the lack of a good text book at undergraduate level. Tons of great books for developers and learners, but with the exception of Orwant's Algorithms book (and possibly Advanced Perl Programming and Higher Order Perl), there are no books for learning Computer Science with Perl. Team up with a bunch of university lecturers and try and give chromatic a run for his money. Your timing is good, all the tools are ready. You just need to prepare the ground.
after some more thinking I must agree with most what Marius said. Technically Perl has easy solutions for ePerl I described.. after finding something close to what I want ( Schwern's Perl5i ), I must say I won't be wasting time for ePerl..
Mainly because, I am convinced that Perl Foundation should do more to market Perl for education.
Some other ideas I came across:
* pyconuk 2014 had 2 days education track
* Applications like Pyland would be great
* It might be great to adjust Perl for different levels, something like staging Perl, i.e. allow only if statements for 5th grade pupils, allow feature x for 6th grade pupils etc. etc. obviously that fits syllabus and government requirements.